The fourth most common and second leading cause of cancer-related death around the world is gastric cancer. It is estimated that the world standardized incidence of gastric cancer is about 16.2/100,000 persons per year. The only prognosis method for gastric cancer is the International Union Against Cancer Tumor-Node-Metastasis (TMN) staging system, in which the degree of tumor penetration and nodal status are the two main prognostic indicators in patients without distant metastatic disease. It turns out that surgery is an option for early stage patients, but 50% of gastric cancer patients suffer from tumor relapse even after radical surgery. Hence, the current staging system does not seem to accurately predict individual patient risk of cancer recurrence.

A study performed by Bertazza et al. (2009), observed the expression of circulating tumor cell-related genes as a prognostic aid to the TNM staging system in gastric carcinoma patients. In the study they examined a total of 70 patients ranging from stage I to IV TNM gastric carcinoma. Quantitative real-time PCR was utilized to identify the expression of four circulating tumor cell-related genes from peripheral blood samples. These genes are carcinoembryonic antigen (CEA), cytokeratin-19 (CK19), vascular endothelial growth factor (VEGF) and Survivin (BIRC5). It was revealed that expression of Survivin, CK19, CEA and VEGF were higher than in normal controls, with Survivin and CK19 having the highest differential expression 98.6% and 97.1% respectively.

Survival analysis TNM staging and Survivin mRNA levels in the peripheral blood were retained as independent prognostic factors. In the end, Survivin proved to add influential prognostic information to the TMN staging system data to better treat gastric carcinoma patients.

Reference:
Survivin gene levels in the peripheral blood of patients with gastric cancer independently predict survival, Loris Bertazza, Simone Mocellin, Alberto Marchet, Pierluigi Pilati, Joseph Gabrieli, Romano Scalerta and Donato Nitti Journal of Translational Medicine December 22 2009, 7:111doi:10.1186/1479-5876-7-111

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